Victoria Duval of the United States leaps in celebration after defeating Samantha Stosur of Australia in the first round of the 2013 U.S. Open on Tuesday in New York. Duval won 5-7, 6-4, 6-4.

NEW YORK — From the earnest explanation of why Gary the Snail is her favorite “SpongeBob SquarePants” character to the name-check of rapper Lil Wayne, Victoria Duval made quite clear that she is very much a 17-year-old kid.

One who just so happened to stun 2011 champion Sam Stosur in the first round of the U.S. Open.

Overcoming the sort of nerves that derive from never before having played this highly ranked an opponent — let alone beaten one — and never before having won a match at a Grand Slam tournament, Duval hopped up and down with arms overhead after pulling off her big surprise at Flushing Meadows, a 5-7, 6-4, 6-4 victory over the 11th-seeded Stosur.

“I don’t even remember match point,” the 296th-ranked American said Tuesday night, less than two hours after closing out Stosur with a forehand winner. “I guess I was really happy. I mean, you could tell by all the jumping I did.”

She wore a white towel around her neck, giggled at her own squeaky-voiced answers, and genuinely seemed to be enjoying the whole experience during a news conference that was a meandering affair, befitting Duval’s bubbly personality — and the long, unique journey that brought her to this point.

Duval, currently based in Bradenton, Fla., was born in Florida, but grew up in her parents’ home country of Haiti. She said that when she was 7, she and some cousins were taken hostage there by robbers.

“It’s not a good memory, so I’ve tried to forget as much as I could about it,” Duval said when the subject was raised. “I don’t remember too much of it anymore, which is great.”

Then, in 2010, when Haiti was rocked by an earthquake, her father was buried in rubble and badly injured, Duval said.

“There’s a lot to be thankful for. I don’t take anything for granted. ... My Dad is really fortunate to be here,” she told the Louis Armstrong Stadium crowd during an on-court interview.

Duval, who needed to go through qualifying to get into the U.S. Open because her ranking is so low, joined eight other American women in the second round of the main draw. Tuesday also was a good day for American men, who went 5-2, led by No. 13 John Isner and No. 26 Sam Querrey.

“We’re obviously trying to make American tennis become what it used to be,” Duval said. “We’re all working toward the same goal. We’re all a tight-knit group. Helping each other is important. I think we’re on an amazing path.”

A group of Americans is slated to play Wednesday, when there will be a mix of first- and second-round matches, including past champions Serena and Venus Williams, 15th-seeded Sloane Stephens, 23rd-seeded Jamie Hampton, and 33-year-old James Blake, who announced the U.S. Open will be the last tournament of his career. Also on the schedule: Andy Murray, the defending men’s champion who added a Wimbledon championship last month.

Until Tuesday, Duval did not own a victory over anyone ranked higher than 69th. She had not faced a woman in the top 20. She only had played one match at a major tournament, a first-round loss to Kim Clijsters at last year’s U.S. Open (which turned out to be the final singles victory of the Belgian’s career).

Stosur was unhappy with the way she played Tuesday, including 10 double-faults and a total of 56 unforced errors, 21 more than Duval.

“I’m not going to be a sore loser and say she didn’t do anything,” said Stosur, an Australian. “But, you know, I think I certainly helped her out there today, that’s for sure.”

Perhaps. But Duval’s game also has benefited from time spent in heady company recently, including mentoring from Billie Jean King and tips from famed tennis coach Nick Bolletieri.

“We have a great relationship,” Duval said. “I call him Uncle Nick.”

Seconding Stosur’s assessment, Duval summed up their match this way: “Although she didn’t play nearly her best today, I played amazing, so I’ll take it.”

And why shouldn’t she? We’ve seen this sort of thing before, and rather recently: In 2009, another 17-year-old American, Melanie Oudin, made it all the way to the quarterfinals in New York by upsetting a series of seeded players, including past champion Maria Sharapova. This year, Oudin lost in U.S. Open qualifying.

Next for Duval, who wears white-framed eyeglasses and a visor on court, is a matchup against Daniela Hantuchova, who has been ranked as high as No. 5 and been a Grand Slam quarterfinalist.

But for an evening, anyway, Duval wanted to relish the biggest win of her nascent career.

And the kid sure seemed to be having a grand ol’ time speaking to reporters, describing herself as “very goofy off the court” and “a child at heart.”

So it made sense that when the subject of the “SpongeBob” cartoon series came up during her media session, she pointed out that “Gary’s cute; Gary doesn’t get enough credit.”

And she brought this up, too: “I heard that Lil Wayne tweeted me. I need to go check that out. I don’t have Twitter. I’m going to go hit that up.”